Hello to all;
I appreciate the information Tod, KØTO, provided regarding his experience
refurbishing an aluminum tower.
I wonder if loose pins in place of bolts holding sections together adequately
prevent fretting corrosion, which occurs when materials that are dependent upon
self oxidation to prevent corrosion experience movement in the joints that
continuously erodes the protective oxide and exposes base metal to fresh
oxidation or other corrosion. I don't have an authoritative reference at hand,
but will look for it if anyone wishes more information. The pins sound less
expensive than SS bolts!
If the holes in the tower legs are corroded, it is recommended that they be
reamed to fit the fasteners to minimize relative movement of one leg on the
other.
I am considering paralleling each leg of a Universal tower with a continuous
aluminum wire to protect against any resistive joints that might add to the
impedance to lightning current. I can calculate the reactive impedance, but
have no data on resistive impedance in the joints. Anyone able to offer data
or references?
I am also considering ways to ventilate the legs to remove moisture, without
compromising the structure. Any information to share?
73 de WOØW
________________________________________________________________________
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Order online at http://store.eham.net.
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